Hepatitis B virus (“HBV”) is second only to tobacco as a cause of human cancer. The mechanism by which HBV induces cancer is unknown, although it is postulated that it may directly trigger tumor development, or indirectly trigger tumor development through chronic inflammation, cirrhosis and cell regeneration associated with the infection.
Hepatitis B virus has reached epidemic levels worldwide. After a two to six month incubation period in which the host is unaware of the infection, HBV infection can lead to acute hepatitis and liver damage, that causes abdominal pain, jaundice, and elevated blood levels of certain enzymes. HBV can cause fulminant hepatitis, a rapidly progressive, often fatal form of the disease in which massive sections of the liver are destroyed. Patients typically recover from acute viral hepatitis. In some patients, however, high levels of viral antigen persist in the blood for an extended, or indefinite, period, causing a chronic infection. Chronic infections can lead to chronic persistent hepatitis. Patients infected with chronic persistent HBV are most common in developing countries. Chronic persistent hepatitis can cause fatigue, cirrhosis of the liver and hepatocellular carcinoma, a primary liver cancer. In western industrialized countries, high risk groups for HBV infection include those in contact with HBV carriers or their blood samples. The epidemiology of HBV is in fact very similar to that of acquired immunodeficiency syndrome, which accounts for why HBV infection is common among patients with AIDS or HIV-associated infections. However, HBV is more contagious than HIV.
To date, only three drugs have been approved by the FDA for the treatment of chronic HBV infection: interferon alpha, 3TC (Epivir, lamivudine) and adefovir dipivoxil (Hepsera® Gilead Sciences).
FDA Approved Drugs for HBVDrug NameDrug ClassCompanyFDA StatusIntron AinterferonSchering-FDA-(interferon α-2b)Ploughapproved3TC (lamivudine;nucleosideGlaxoSmithKlineFDA-Epivir-HBV)analogueapprovedAdefovir dipivoxilnucleotideGilead SciencesFDA-analogueapprovedInterferon Alpha
A manufactured form of interferon is used to treat hepatitis B. This treatment involves the administration of interferon by injection for about four months.
Not all patients respond to interferon, and sometimes retreatment is necessary. In clinical studies, only 45% of patients who were treated for hepatitis B with A (Interferon alpha-2b, recombinant, Schering Corporation) for Injection had no evidence of the hepatitis B virus in their blood over time. In addition, most patients have difficulty tolerating interferon treatment, which causes severe flu-like symptoms, weight loss, and lack of energy and stamina.
3TC
The (−)-enantiomer of BCH-189 (2′,3′-dideoxy-3′-thiacytidine), also known as 3TC (Epivir, lamivudine) is an antiviral drug that is active against both HIV and HBV. It belongs to the class of drugs called nucleoside analog reverse transcriptase inhibitors (NRTI), which work by blocking production of the reverse transcriptase enzyme that HIV and HBV need in order to replicate. 3TC was originally developed for the treatment of HIV, however, researchers discovered that 3TC also works against the hepatitis B virus. In December 1998, the U.S. Food and Drug Administration (FDA) approved Epivir HBV for the treatment of hepatitis B virus infection.
Although 3TC efficiently inhibits HBV replication, the slow kinetics of viral elimination during 3TC therapy (Nowak, M., S. Bonhoeffer, et al. 1996. Proc. Natl. Acad. Sci. USA 93:4398-4402) and the spontaneous viral genome variability lead to the emergence of drug-resistant mutants which carry mutations affecting the reverse transcriptase (RT) domain (Mason, W. S., J. Cullen, et al. 1998. Virology 245:18–32. Nafa, S., S. Ahmed, et al. 2000. Hepatology 32:1078–1088; Melegari, M., P. P. Scaglioni, and J. R. Wands. 1998 Hepatology 27:628–633; Seigneres, B., C. Pichoud, et al. 2000. J. Infect. Dis. 181:1221–1233). Approximately 50% of treated patients develop viral resistance after 3 years of treatment with 3TC (Leung, N. W., C. L. Lai, et al. 2001. Hepatology 33:1527–1532). Resistance to nucleoside analogs is associated with substitutions in the nucleic acid sequence of the polymerase gene causing changes in the amino acid sequence of the HBV RT, notably in the YMDD motif within the catalytic site. The most common polymerase variant is the rtL180M-plus-M204V change (according to the recent genotype-independent nomenclature for HBV drug-resistant variants) (Stuyver, L. J., S. A. Locarnini, et al. 2001. Hepatology 33:751–757) that associates a mutation in the catalytic site (rtM204V) with a compensatory mutation in the B domain of the RT (rtL180M) which provides a higher replication capacity to the catalytic site variant (Allen, M. I., M. Deslauriers, et al. 1998. Hepatology 27:1670–1677. Chayama, K, Y. Suzuki, et al. 1998. Hepatology 27:1711–1716. Melegari, M., P. P. Scaglioni, and J. R. Wands. 1998. Hepatology 27:628–633. Ono, S. K., N. Kato, et al. 2001. J. Clin. Investig. 107:449–455. Seigneres, B., S. Aguesse-Germon, et al. 2001. J. Hepatol. 34:114–122).
Adefovir Dipivoxil (Hepsera)
On Sep. 20, 2002, the U.S. Food and Drug Administration approved adefovir dipivoxil for the treatment of chronic hepatitis B. HEPSERA™ is the tradename for adefovir dipivoxil, a diester prodrug of adefovir. Adefovir is an acyclic nucleotide analogue of adenosine monophosphate that inhibits the hepatitis B virus (HBV) DNA polymerase by competing with the natural substrate deoxyadenosine triphosphate and by causing DNA chain termination after its incorporation into viral DNA. The chemical name of adefovir dipivoxil is 9-[2-[bis[(pivaloyloxy)methoxy]phosphinyl]methoxy]-ethyl]adenine. Adefovir is phosphorylated to the active metabolite, adefovir diphosphate, by cellular kinases. See, for example, U.S. Pat. Nos. 5,641,763 and 5,142,051, entitled, N-phosphonylmethoxyalkyl derivatives of pyrimidine and purine bases and a therapeutical composition therefrom with antiviral activity.
Resistant HBV Strains
Lamivudine is an L-nucleoside for the treatment of HBV that frequently results in the selection of resistant strains of virus that can discriminate between the unnatural L-nucleoside and the D-nucleoside, the natural substrates, and in particular the single mutants, YMDD mutant (M552I or M552V) and L528M, and the double mutant (L528M/M552V). See U.S. Pat. Nos. 6,242,187 and 6,265,181; and International Publication No. WO 01/04358. See also: Ahmed et al. “Early Detection of Viral Resistance by Determination of Hepatitis B Virus Polymerase Mutations in Patients Treated by Lamivudine for Chronic Hepatitis B” Hepatology, 2000, 32 (5), 1078–1088; Ono et al. “The polymerase L528M mutation cooperates with nucleotide binding-site mutations, increasing hepatitis B virus replication and drug resistance” Journal of Clinical Investigation, February 2001, 107 (4), 449–455; Allen “Identification and Characterization of Mutations in Hepatitis B Virus Resistant to Lamivudine” Hepatology, 1998, 7 (6), 1670–1677; Das et al. “Molecular Modeling and Biochemical Characterization Reveal the Mechanism of Hepatitis B virus Polymerase Resistance to Lamivudine (3TC) and Emtricitabine (FTC)” Journal of Virology, May 2001, 75 (10), 4771–4779; Delaney “Cross-Resistance Testing of Antihepadnaviral Compounds using Novel Recombinant Baculoviruses which Encode Drug-Resistant Strains of Hepatitis B Virus” Antimicrobial Agents and Chemotherapy, June 2001, 45 (6), 1705–1713; Fu “Role of Additional Mutations outside the YMDD Motif of Hepatitis B Virus Polymerase in L-(−)-SddC (3TC) Resistance” Biochemical Pharmacology, 1998, 55 (10), 1567–1572; Fu “Sensitivity of L-(−)-2′,3′-Dideoxythiacytidine Resistant Hepatitis B Virus to Other Antiviral Nucleoside Analogues” Biochemical Pharmacology, 1999, 57 (12), 1351–1359; Gauthier “Quantitation of Hepatitis B Viremia and Emergence of YMDD Variants in Patients with Chronic Hepatitis B Treated with Lamivudine” The Journal of Infection Diseases, December 1999, 180, 1757–1762; Kioko “YMDD Motif in Hepatitis B Virus DNA Polymerase Influences on Replication and Lamivudine Resistance: A Study by In Vitro Full-Length viral DNA Transfection” Hepatology, March 1999, 29 (3), 939–945; Kioko “Susceptibility of lamivudine-resistant hepatitis B virus to other reverse transcriptase inhibitors” The Journal of Clinical Investigation, June 1999, 3 (12), 1635–1640; Zoulim “Drug therapy for chronic hepatitis B: antiviral efficacy and influence of hepatitis B virus polymerase mutations on the outcome of therapy” Journal of Hepatology, 1998, 29, 151–168; and Ying et al. J Viral Hepat., March 2000, 7 (2), 161–165.
In controlled clinical studies of lamivudine (100 mg qd) administered to HBV-infected patients, the prevalence of YMDD-mutant HBV was 14 to 32% after one year of treatment and as much as 58% after two to three years of treatment. Mutant virus was associated with evidence of diminished treatment response relative to lamivudine-treated patients without YMDD mutations. Ono et al. The Journal of Clinical Investigation, 2001, 107 (4), 449–455.
Genotypic analysis of viral isolates obtained from patients with renewed HBV replication while receiving lamivudine suggests that a reduction in HBV sensitivity to lamivudine is associated with mutations resulting in a methionine to valine or isoleucine substitution in the YMDD motif of the catalytic domain of HBV polymerase (position 552) and a leucine to methionine substitution at position 515 or 528 (depending on the genotype/subtype of HBV).
At the present time, there is no cell-based HBV infection system that can be used to assess the activity of antiviral agents against cells infected with lamivudine-resistant HBV isolates from patients. The duck HBV (DHBV) in vitro model has not proved useful to select drug-resistant mutations because the primary duck hepatocytes used in this model cannot be sustained for more than a few weeks in cell culture. The relevance of selection of drug-resistant mutants in the woodchuck in vivo model is dubious because the spectrum of lamivudine-resistant mutants in the woodchuck does not match that identified in HBV-infected patients.
Interferons
Interferon is a protein made naturally by the body to modulate the immune system and to regulate other cell functions. The main classes of interferons are interferon alpha, interferon beta, interferon gamma, interferon omega and interferon tau. Interferons can be modified to increase stability in vivo, such modifications include pegylation, or other means to enhance the stability of the molecule.
Examples of the interferon alpha class of interferons include interferon alpha-2a, interferon alpha-2b, pegylated interferon alpha-2a, pegylated interferon alpha-2b ROFERON®-A (interferon alpha-2a, Roche), PEGASYS® (pegylated interferon alpha-2a, Roche), INTRON®A (Interferon alpha-2b, Schering Corporation), PEG-INTRON® (pegylated Interferon alpha-2b, Schering Corporation), consensus interferon, INFERGEN (interferon alphacon-1) by InterMune, OMNIFERON (natural interferon) by Viragen, ALBUFERON by Human Genome Sciences, Oral Interferon Alpha by Amarillo Biosciences, and SuperFeron (natural human multi-subtype IFN-alpha, Genetrol, Inc.).
Other types of interferon include: interferon beta, interferon gamma, interferon tau, interferon omega, REBIF (interferon beta-1a) by Ares-Serono, Omega Interferon by BioMedicine, interferon gamma-1b by InterMune, and HuFeron (human IFN-beta, Genetrol, Inc.).
Daily treatments with α-interferon, a genetically engineered protein, have shown promise. A human serum-derived vaccine has also been developed to immunize patients against HBV. Vaccines have been produced through genetic engineering. While the vaccine has been found effective, production of the vaccine is troublesome because the supply of human serum from chronic carriers is limited, and the purification procedure is long and expensive. Further, each batch of vaccine prepared from different serum must be tested in chimpanzees to ensure safety. In addition, the vaccine does not help the patients already infected with the virus.
An essential step in the mode of action of purine and pyrimidine nucleosides against viral diseases, and in particular, HBV and HIV, is their metabolic activation by cellular and viral kinases, to yield mono-, di- and triphosphate derivatives. The biologically active species of many nucleosides is the triphosphate form, which inhibits DNA polymerase or reverse transcriptase, or causes chain termination.
A number of synthetic nucleosides have been identified that exhibit activity against HBV. As stated supra, the (−)-enantiomer of BCH-189 (2′,3′-dideoxy-3′-thiacytidine), known as 3TC, has been approved for the treatment of hepatitis B. See U.S. Pat. No. 5,532,246 as well as EPA 0 494 119 A1 filed by BioChem Pharma, Inc.
Adefovir (9-{2-(phosphonomethoxy)ethyl}adenine, also referred to as PMEA or ({2-(6-amino-9H-purin-9-yl)ethoxy}methylphosphonic acid), also has been approved in the United States for the treatment of patients infected with hepatitis B virus. See, for example, U.S. Pat. Nos. 5,641,763 and 5,142,051. Resistance to adefovir treatment in patients with HBV has been noted.
β-2-Hydroxymethyl-5-(5-fluorocytosin-1-yl)-1,3-oxathiolane (“FTC”), claimed in U.S. Pat. Nos. 5,814,639 and 5,914,331 to Liotta et al., exhibits activity against HBV. See Furman et al., “The Anti-Hepatitis B Virus Activities, Cytotoxicities, and Anabolic Profiles of the (−) and (+) Enantiomers of cis-5-Fluoro-1-{2-(Hydroxymethyl)-1,3-oxathiolane-5-yl}-Cytosine” Antimicrobial Agents and Chemotherapy, December 1992, 2686–2692; and Cheng, et al., Journal of Biological Chemistry, 1992, 267 (20), 13938–13942.
U.S. Pat. Nos. 5,565,438, 5,567,688 and 5,587,362 (Chu, et al.) disclose the use of 2′-fluoro-5-methyl-β-L-arabinofuranolyluridine (L-FMAU) for the treatment of hepatitis B and Epstein Barr virus.
Penciclovir (PCV; 2-amino-1,9-dihydro-9-{4-hydroxy-3-(hydroxymethyl)butyl}-6H-purin-6-one) has established activity against hepatitis B. See U.S. Pat. Nos. 5,075,445 and 5,684,153.
Yale University and The University of Georgia Research Foundation, Inc. disclose the use of L-FDDC (5-fluoro-3′-thia-2′,3′-dideoxycytidine) for the treatment of hepatitis B virus in WO 92/18517.
Other drugs explored for the treatment of HBV include adenosine arabinoside, thymosin, acyclovir, phosphonoformate, zidovudine, (+)-cyanidanol, quinacrine, and 2′-fluoroarabinosyl-5-iodouracil.
U.S. Pat. Nos. 5,444,063 and 5,684,010 to Emory University disclose the use of enantiomerically pure β-D-1,3-dioxolane purine nucleosides to treat hepatitis B.
WO 96/40164 filed by Emory University, UAB Research Foundation, and the Centre National de la Recherche Scientifique (CNRS) discloses a number of β-L-2′,3′-dideoxynucleosides for the treatment of hepatitis B.
WO 95/07287 also filed by Emory University, UAB Research Foundation, and the Centre National de la Recherche Scientifique (CNRS) discloses 2′- or 3′-deoxy and 2′,3′-dideoxy-β-L-pentofuranosyl nucleosides for the treatment of HIV infection.
WO96/13512 filed by Genencor International, Inc., and Lipitek, Inc., discloses the preparation of L-ribofuranosyl nucleosides as antitumor agents and virucides.
WO95/32984 discloses lipid esters of nucleoside monophosphates as immuno-suppresive drugs.
DE 4224737 discloses cytosine nucleosides and their pharmaceutical uses.
Tsai et al., in Biochem. Pharmacol. 1994, 48(7), 1477–81, disclose the effect of the anti-HIV agent 2′-β-D-F-2′,3′-dideoxynucleoside analogs on the cellular content of mitochondrial DNA and lactate production.
Galvez, J. Chem. Inf Comput. Sci. 1994, 35(5), 1198–203, describes molecular computation of β-D-3′-azido-2′,3′-dideoxy-5-fluorocytidine.
Mahmoudian, Pharm. Research 1991, 8(1), 43–6, discloses quantitative structure-activity relationship analyses of HIV agents such as β-D-3′-azido-2′,3′-dideoxy-5-fluorocytidine.
U.S. Pat. No. 5,703,058 discloses (5-carboximido or 5-fluoro)-(2′,3′-unsaturated or 3′-modified) pyrimidine nucleosides for the treatment of HIV or HBV.
Lin et al., discloses the synthesis and antiviral activity of various 3′-azido analogues of β-D-nucleosides in J. Med. Chem. 1988, 31 (2), 336–340.
WO 00/3998 filed by Idenix Pharmaceuticals, Ltd. discloses methods of preparing substituted 6-benzyl-4-oxopyrimidines, and the use of such pyrimidines for the treatment of HIV.
Idenix Pharmaceuticals, Ltd. discloses 2′-deoxy-β-L-erythropentofurano-nucleosides, and their use in the treatment of HBV in U.S. Pat. Nos. 6,395,716; 6,444,652; 6,566,344 and 6,539,837. See also WO 00/09531. A method for the treatment of hepatitis B infection in humans and other host animals is disclosed that includes administering an effective amount of a biologically active 2′-deoxy-β-L-erythro-pentofuranonucleoside (alternatively referred to as β-L-dN or a β-L-2′-dN) or a pharmaceutically acceptable salt, ester or prodrug thereof, including β-L-deoxyribothymidine (β-L-dT), β-L-deoxyribocytidine (β-L-dC), β-L-deoxyribouridine (β-L-dU), β-L-deoxyribo-guanosine (β-L-dG), β-L-deoxyriboadenosine (β-L-dA) and β-L-deoxyriboinosine (β-L-dI), administered either alone or in combination, optionally in a pharmaceutically acceptable carrier. 5′ and N4 (cytidine) or N6 (adenosine) acylated or alkylated derivatives of the active compound, or the 5′-phospholipid or 5′-ether lipids were also disclosed.
von Janta-Lipinski et al. J. Med. Chem., 1998, 41 (12), 2040–2046 disclose the use of the L-enantiomers of 3′-fluoro-modified β-2′-deoxyribonucleoside 5′-triphosphates for the inhibition of hepatitis B polymerases. Specifically, the 5′-triphosphates of 3′-deoxy-3′-fluoro-β-L-thymidine (β-L-FTTP), 2′,3′-dideoxy-3′-fluoro-β-L-cytidine (β-L-FdCTP), and 2′,3′-dideoxy-3′-fluoro-β-L-5-methylcytidine (β-L-FMethCTP) were disclosed as effective inhibitors of HBV DNA polymerases. In addition, von Janta-Lipinski et al. discloses the biological activity of the triphosphate of β-L-thymidine (but not β-L-2′-dC) as a nucleoside inhibitor of endogenous DNA polymerases of HBV and DHBV. However, only triphosphorylated β-L-thymidine was evaluated, not the claimed unphosphorylated form, and there is no comment in the article on whether those β-L-nucleosides are phosphorylated in cells or in vivo or, more importantly, there is no comment on the efficacy of phosphorylation of β-L-thymidine in vivo. Because of this, the article does not teach that β-L-thymidine would have any hepatitis B activity in a cell or in vivo. See also WO 96/1204.
European Patent Application No. 0 352 248 A1 to Johansson et al. discloses the use of L-ribofuranosyl compounds for the treatment of hepatitis B.
Lin et al. “Synthesis of Several Pyrimidine L-Nucleoside Analogues as Potential Antiviral Agents” Tetrahedron, 1995, 51 (4), 1055–1068, discusses that β-L-5-iodo-2′-deoxyuridine (β-L-IUdR, compound 7) is active against herpes infection and various other DNA viruses, that BVdU and β-L-BV-ara-U are also active against herpes, β-L-BV-ara-U is active against varicella-zoster virus; and that 2′,3′-dideoxy-L-azacytidine was found to be active against HBV.
U.S. Pat. Publication No. 20030083306 to Idenix Pharmaceuticals, Ltd. discloses 3′-prodrugs of 2′-deoxy-β-L-nucleosides for the treatment of HBV. See also WO 01/96353.
U.S. Pat. No. 4,957,924 to Beauchamp discloses various therapeutic esters of acyclovir.
In the Apr. 17–21, 2002 European Association for the Study of the Liver meeting in Madrid, Spain, Sühnel et al. of Gilead Sciences, Inc. presented a poster indicating that combinations of adefovir with β-L-2′deoxythymidine produce additive antiviral effects against HBV in vitro.
At the same meeting, Delaney et al. of Gilead Sciences, Inc. presented an oral presentation indicating that select strains of lamivudine-resistant HBV, i.e., HBV with a single mutation at the L528M (rtL180M) or M552I (rtM204I), or with a double mutation at L528M (rtL528M) and M552V (rtM204V), are cross-resistant to L-dT and L-dC in vitro.
Treatments for hepatitis B infection are also described in Lok and McMahon, AASLD Practice Guidelines, pp. 1225–1241 (2001) including treatment with interferons. Eastern woodchucks chronically infected with the woodchuck hepatitis virus (WHV) were used as a model of HBV infection to study the antiviral effect of 1-(2-fluoro-5-methyl-β-L-arabinofuranosyl)-uracil (L-FMAU) and WHV surface antigen vaccine. The humoral and cellular immunity associated with the combination of L-FMAU and vaccine resembled that observed in self-limited WHV infection. Menne et al., J Virology, 76(1):5305–5314 (2002).
WO 98/23285 discloses a method for the treatment or prophylaxis of hepatitis B virus infections in a human or animal patient which comprises administering to the patient effective or prophylactic amounts of penciclovir (or a bioprecursor thereof such as famciclovir) and alpha-interferon.
Examples of antiviral agents that have been identified as active against the hepatitis B virus include: Agents currently in clinical development, include:
Drug NameDrug ClassCompanyFDA StatusIntron AinterferonSchering-PloughFDA-approved(interferon α-2b)Epivir-HBVnucleoside analogueGlaxoSmithKlineFDA-approved(lamivudine; 3TC)Adefovir dipivoxilnucleotide analogueGilead SciencesPhase III*(NDA filedMarch 2002)Coviracilnucleoside analogueTrianglePhase III(emtricitabine;PharmaceuticalsFTC)Entecavirnucleoside analogueBristol-Myers SquibbPhase IIIClevudinenucleoside analogueTrianglePhase II(L-FMAU)PharmaceuticalsACH 126, 443nucleoside analogueAchillionPhase II(L-Fd4C)PharmaceuticalsAM 365nucleoside analogueAmradPhase II (Asiaand Australia)DAPDnucleoside analogueTrianglePhase IIPharmaceuticalsLdT (telbavudine)nucleoside analogueIdenixPhase IIXTL 001monoclonal antibodyXTL BiopharmPhase II (Israel)TheradigmImmune stimulantEpimmunePhase IIZadaxin**Immune stimulantSciClonePhase II(thymosin)with Epivir-HBVEHT 899viral proteinEnzo BiochemPhase II (Israel)HBV DNA vaccineImmune stimulantPowderJect (UK)Phase IMCC 478nucleoside analogueEli LillyPhase I(Germany)valLdCnucleoside analogueIdenixPhase I(valtorcitabine)ICN 2001nucleoside analogueICNPreclinicalFluoro L and Dnucleoside analoguePharmassetPreclinicalnucleosidesRacivirnucleoside analoguePharmassetPreclinicalRobustaflavonenucleoside analogueAdvanced LifePreclinicalSciences**Zadaxin: orphan drug approval in US
Post Exposure and/or Post Liver Transplant TherapiesHBVBayHepBimmuneglobulinBayer (US)FDA-approvedanti-HBVCangeneNDA submittedhepatitis Bimmuneglobulin(Canada)2001Nabi-HBHBVNabiFDA-approvedimmuneglobulinMark Nelson, MD. Selected Highlights from Drug Development for Antiretroviral Therapies 2001 (Hep DART 2001) Dec. 16–20, 2001, Maui, Hi.; Selected Highlights from American Association for the Study of Liver Diseases 52nd Annual Meeting (52nd AASLD). Nov. 9–13, 2001. Dallas, Tex.; Report on Hepatitis B from Digestive Disease Week 2001; May 20–23, 2001, Atlanta, Ga.
U.S. Application No. 20020098199, published Jul. 25, 2002, discloses immunostimulatory sequences for the treatment of HBV and HCV.
U.S. Pat. No. 6,225,292, assigned to The Regents of the University of California and Dynavax Technologies Corp., discloses oligonucleotides which inhibit the immunostimulatory activity of ISS-ODN (immunostimulatory sequence oligodeoxynucleotides) as well as methods for their identification and use. The disclosed oligonucleotides of are useful in controlling therapeutically intended ISS-ODN adjuvant activity as well as undesired ISS-ODN activity exerted by recombinant expression vectors, such as those used for gene therapy and gene immunization. The oligonucleotides also have anti-inflammatory activity useful in reducing inflammation in response to infection of a host with ISS-ODN containing microbes, in controlling autoimmune disease and in boosting host Th2 type immune responses to an antigen. The patent also encompasses pharmaceutically useful conjugates of the oligonucleotides of the invention (including conjugate partners such as antigens and antibodies).
U.S. Pat. No. 6,589,940, assigned to Dynavax Technologies Corp., discloses immunostimulatory oligonucleotide compositions. These oligonucleotides comprise an immunostimulatory octanucleotide sequence. These oligonucleotides can be administered in conjunction with an immunostimulatory peptide or antigen. Methods for modulating an immune response upon administration of the oligonucleotide are also disclosed. In addition, an in vitro screening method to identify oligonucleotides with immunostimulatory activity is provided.
U.S. Pat. No. 6,562,798, assigned to Dynavax Technologies Corp., discloses immunomodulatory oligonucleotide compositions, including immunostimulatory hexanucleotide sequence comprising a modified cytosine. These oligonucleotides can be administered in conjunction with an immunomodulatory peptide or antigen. Methods of modulating an immune response upon administration of the oligonucleotide comprising a modified immunostimulatory sequence are also disclosed.
PCT WO 03/014316 A2, assigned to Dynavax Technologies Corp., discloses compositions and methods for immunomodulation of individuals. Immunomodulation is accomplished by administration of immunomodulatory polynucleotide/microcarrier (IMO/MC) complexes comprising 3–6mer immunomodulatory oligonucleotides. The IMO/MC complexes may be covalently or non-covalently bound. Also disclosed are immunomodulatory compositions comprising a 3–6mer IMO encapsulated in an MC.
PCT WO 03/000922 A2, assigned to Dynavax Technologies Corp., discloses immunomodulatory compounds and methods for immunomodulation of individuals using the immunomodulatory compounds.
PCT WO 02/052002 A2, assigned to Dynavax Technologies Corp., discloses immunomodulatory polynucleotides and methods for immunomodulation of individuals using the immunomodulatory polynucleotides.
PCT WO 01/68144A2 and PCT WO0168143A2 assigned to Dynavax Technologies Corp., disclose compositions and methods for immunomodulation of individuals. Immunomodulation is accomplished by administration of immunomodulatory polynucleotide/microcarrier (IMP/MC) complexes. The IMP/MC complexes may be covalently or non-covalently bound, and feature a polynucleotide comprising at least one immunostimulatory sequence bound to a biodegradable microcarrier or nanocarryier.
PCT WO 01/68117 A2, assigned to Dynavax Technologies Corp., discloses methods for the treatment of papillomavirus infections. A polynucleotide comprising an immunstimulatory sequence is administered to an individual who has been exposed to or infected by papillomavirus. The polynucleotide is not administered with papillomavirus antigen. Administration of the polynucleotide results in amelioration of symptoms of papillomavirus infection.
PCT WO 01/68078 A2, assigned to Dynavax Technologies Corp., discloses methods for the treatment of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. A polynucleotide comprising an immunostimulatory sequence is administered to an individual who has been exposed to or infected by HBV and/or HCV. The polynucleotide is not administered with a HCV or HBV antigen. Administration of the polynucleotide results in amelioration of symptoms of HBV and/or HCV infection.
PCT WO 01/68077 A3, assigned to Dynavax Technologies Corp., discloses methods of suppression, prevention, and/or treatment of infection by viruses. A polynucleotide comprising an immunostimulatory sequence (an “ISS”) is administered to an individual who is at risk of being exposed to, has been exposed to or is infected with a virus. The ISS-containing polynucleotide is administered without any antigens of the virus. Administration of the ISS-containing polynucleotide results in reduced incidence and/or severity of one or more symptoms of virus infection.
PCT WO 01/12223 A2, assigned to Dynavax Technologies Corp., discloses methods of modulating an immune response to a second antigen which entail administration of a first antigen and an immunostimulatory polynucleotide. Modulation of the immune response is generally manifested as stimulation of a Th1 response.
PCT WO 00/21556 A1, assigned to Dynavax Technologies Corp., discloses anti-viral immunomodulatory compositions comprising immunostimulatory polynucleotides and HIV antigens, such as gp120. Methods for modulating an immune response upon administration of the oligonucleotide and antigen compositions are also disclosed.
PCT WO 00/16804 A1, assigned to Dynavax Technologies Corp., discloses methods of treating IgE-associated disorders and compositions for use therein. The methods are particularly useful in treatment of allergies and allergy-related disorders. The methods generally comprise administering an IgE inhibitor (such as anti-IgE antibody) and an antigen and/or immunostimulatory polynucleotide sequence (ISS). These combination methods offer significant advantages, such as allowing more aggressive therapy while reducing unwanted side effects, such as anaphylaxis.
PCT WO 99/62923 A2, assigned to Dynavax Technologies Corp., discloses oligonucleotides comprise an immunostimulatory hexanucleotide sequence comprising a modified cytosine. These oligonucleotides can be administered in conjunction with an immunomodulatory peptide or antigen. Methods of modulating an immune response upon administration of the oligonucleotide comprising a modified immunostimulatory sequence are also disclosed.
PCT WO 98/55495 A2, assigned to Dynavax Technologies Corp., discloses immunostimulatory oligonucleotide composition including immunostimulatory octanucleotide sequence. These oligonucleotides can be administered in conjunction with an immunostimulatory peptide or antigen. Methods for modulating an immune response upon administration of the oligonucleotide are also disclosed. In addition, an in vitro screening method to identify oligonucleotides with immunostimulatory activity is also disclosed.
PCT WO 03/015711 A2, assigned to Coley Pharmaceutical Group, Inc., discloses a class of immunostimulatory nucleic acids having at least two functionally and structurally defined domains. This class of combination motif immunostimulatory nucleic acids activates an immune response and is useful for treating a variety of immune related disorders such as cancer, infectious disease, and allergic disorders. The nucleic acids also stimulate activation of natural killer cells and production of type 1 interferon.
U.S. Pat. No. 6,406,705, assigned to Coley Pharmaceutical Group, Inc., discloses methods and products utilizing a synergistic combination of immunostimulatory oligonucleotides having at least one unmethylated CpG dinucleotide (CpG ODN) and a non-nucleic acid adjuvant. Such combinations of adjuvants may be used with an antigen or alone. Methods and products utilizing immunostimulatory oligonucleotides having at least one unmethylated CpG dinucleotide (CpG ODN) for induction of cellular immunity in infants are also disclosed.
U.S. Pat. No. 6,339,068, assigned to Coley Pharmaceutical Group, Inc., discloses DNA vaccine vectors that can be improved by removal of CpG-N motifs and optional addition of CpG-S motifs. In addition, for high and long-lasting levels of expression, the optimized vector should include a promoter/enhancer that is not down-regulated by the cytokines induced by the immunostimulatory CpG motifs. Vectors and methods of use for immunostimulation are provided herein. The invention also provides improved gene therapy vectors by determining the CpG-N and CpG-S motifs present in the construct, removing stimulatory CpG (CpG-S) motifs and/or inserting neutralizing CpG (CpG-N) motifs, thereby producing a nucleic acid construct providing enhanced expression of the therapeutic polypeptide.
U.S. Pat. No. 6,239,116, assigned to Coley Pharmaceutical Group, Inc., discloses nucleic acid sequences containing unmethylated CpG dinucleotides that modulate an immune response including stimulating a Th1 pattern of immune activation, cytokine production, NK lytic activity, and B cell proliferation are disclosed. The sequences are also useful a synthetic adjuvant.
U.S. Pat. No. 6,207,646, assigned to Coley Pharmaceutical Group, Inc., discloses Nucleic acids containing unmethylated CpG dinucleotides and therapeutic utilities based on their ability to stimulate an immune response and to redirect a Th2 response to a Th1 response in a subject are disclosed.
U.S. Pat. No. 6,194,388, assigned to Coley Pharmaceutical Group, Inc., discloses oligonucleotides containing unmethylated CpG dinucleotides and therapeutic utilities based on their ability to stimulate an immune response in a subject are disclosed. Also disclosed are therapies for treating diseases associated with immune system activation that are initiated by unmethylated CpG dinucleotides in a subject comprising administering to the subject oligonucleotides that do not contain unmethylated CpG sequences (i.e. methylated CpG sequences or no CpG sequence) to outcompete umethylated CpG nucleic acids for binding. Further disclosed are methylated CpG containing dinucleotides for use antisense therapies or as in vivo hybridization probes, and immunoinhibitory oligonucleotides for use as antiviral therapeutics.
U.S. publication no. 20030091599 A1, assigned to Coley Pharmaceutical Group, Inc., discloses methods and products utilizing a synergistic combination of immunostimulatory oligonucleotides having at least one unmethylated CpG dinucleotide (CpG ODN) and a non-nucleic acid adjuvant. Such combinations of adjuvants may be used with an antigen or alone. The publication also relates to methods and products utilizing immunostimulatory oligonucleotides having at least one unmethylated CpG dinucleotide (CpG ODN) for induction of cellular immunity in infants.
PCT WO 03/031573 A2, assigned to Coley Pharmaceutical Group, Inc., discloses compositions and methods are provided to identify, characterize, and optimize immunostimulatory compounds, their agonists and antagonists, working through TLR3.
PCT WO 03/012061 A2, assigned to Coley Pharmaceutical Group, Inc., discloses methods and compositions relating to a dentritic cell expression database.
PCT WO 02/069369 A2, assigned to Coley Pharmaceutical Group, Inc., discloses immunostimulatory compositions described as CpG-like nucleic acids are provided, including nucleic acids having immunostimulatory characteristics of CpG nucleic acid, despite certain substitutions of C, G, or C and G of the CpG dinucleotide. The substitutions can include, among others, exchange of methylated C for C, inosine for G, and ZpY for CpG, where Z is Cytosine or dSpacer and Y is inosine, 2-aminopurine, nebularine, or dSpacer. Also disclosed are methods for inducing an immune response in a subject using the CpG-like nucleic acids. The methods are useful in the treatment of a subject that has or is at risk of developing an infectious disease, allergy, asthma, cancer, anemia, thrombocytopenia, or neutropenia.
PCT WO 01/95935 A1, assigned to Coley Pharmaceutical Group, Inc., discloses methods and products for inducing an immune response using immunostimulatory nucleic acids. In particular the immunostimulatory nucleic acids preferentially induce a Th2 immune response. The invention is useful for treating and preventing disorders associated with a Th1 immune response or for creating a Th2 environment for treating disorders that are sensitive to Th2 immune responses.
PCT WO 01/22990 A2, assigned to Coley Pharmaceutical Group, Inc., discloses methods and compositions for extending the clinical utility of IFN-‘alpha’ in the treatment of a variety of viral and proliferative disorders. Also disclosed are methods which increase the efficacy of IFN-‘alpha’ treatment and reduce IFN-‘alpha’ treatment-related side effects. In addition, methods are provides for supporting the survival and for activating natural interferon producing cells (IPCs) in vitro without exogenous IL-3 or GM-CSF.
PCT WO 01/22972 A2, assigned to Coley Pharmaceutical Group, Inc., discloses immunostimulatory nucleic acid compositions and methods of using the compositions. The T-rich nucleic acids contain poly T sequences and/or have greater than 25% T nucleotide residues. The TG nucleic acids have TG dinucleotides. The C-rich nucleic acids have at least one poly-C region and/or greater than 50% c nucleotides. These immunostimulatory nucleic acids function in a similar manner to nucleic acids containing CpG motifs. The invention also encompasses preferred CpG nucleic acids.
In light of the fact that hepatitis B virus has reached epidemic levels worldwide, and has severe and often tragic effects on the infected patient, there remains a strong need to provide new effective pharmaceutical agents to treat humans infected with the drug-resistant virus, i.e., lamivudine resistant HBV, that have low toxicity to the host.
Therefore, it is an object of the present invention to provide compounds, compositions and methods for the treatment and/or prophylaxis of a lamivudine resistant HBV infection in a host, such as human patients.
It is another object of the present invention to provide compounds, compositions and methods for the prevention of a resistant HBV mutant, for example YMDD HBV (M552V), infection in a naïve host, such as human patients.
It is still another object of the present invention to provide compounds, compositions and methods for the treatment of patients infected with a drug resistant form of HBV.
It is yet another object of the present invention to provide effective combination therapies compositions for the treatment of treatment of HBV and/or the suppression or prevention of the expression of resistant HBV strains in a patient.